Fasten your seatbelt, we are going vertical !
It won't reach the vertical stage until at least 5 digits.
We're still all early adopters.
When it reaches the vertical stage, how much do you think it will rise per day? (on average). When will we hit moves of over $100 per day?
It's anyone's guess but I figure by the time it hits 12k-25k it should be pretty well vertical.
How long it stays vertical before starting to level out from saturation is also a tough call but I doubt it will last much past 300k-400k.
It depends on a lot of things, from the final extent of adoption to how many coins are lost before mining is done, and of course whether or not there is an event that breaks the protocol and destroys Bitcoin completely.